Electrical socket



Dec;

Filed Dec. 24, 1963 1955 L. A. COHEN 3,222,631

ELECTRICAL SOCKET 2 Sheets-Sheet 1 INVENTOR. LEONARD A. COHEN W QSQLAQ ATTORNEY Dec. 7, 1965 L. A. COHEN ELECTRICAL SOCKET 2 Sheets-Sheet 2 Filed Dec. 24, 1963 4 I my Hm mm IWI V I III INVENTOR. LEONARD A. COHEN 6mm 74. M

ATTORNEY United States Patent 3,222,631 ELECTRICAL SOCKET Leonard A. Cohen, 224 Old Lancaster Road, Merion, Pa. Filed Dec. 24, 1963, Ser. No. 333,105 4 Claims. (Cl. 339-40) This invention primarily relates to a novel electric socket or receptacle adapted to receive an electric plug for connecting said plug to a source of electrical energy.

Electric sockets or receptacles used in wall outlets usually have their contact elements exposed to the exterior of the wall. Since the contacts are continuously energized, they represent a source of danger for electrical shocks and short circuits. It is possible to cause a short circuit by the insertion of a wire or other metal object such as a screwdriver into one of the entranceways of the socket. Small children usually fail to appreciate this danger and are often injured by their own curiosity.

Accordingly, it is the primary object of this invention to disclose an electrical socket incorporating safety apparatus for blocking access to the electrical contacts therein.

A more specific object of this invention resides in the provision of a slidable shutter positioned in the entranceways of the electrical socket to block access to the electrical contacts. Means are provided for allowing said shutter to be slid to a position exposing said. electrical contacts only upon the continuous and simultaneous linear movement of the prongs of an electrical plug within said entranceways.

A further object of this invention resides in the disclosure of an electrical socket incorporating a slidable shutter normally urged to a position in the entrance passageways in said socket for blocking access to the electrical contact means and means for locking said shutter in its blocking position. Means are also provided in said socket responsive to the insertion only of the prongs of an electrical plug into said entrance means for unlocking said shutter to condition it for sliding movement to a position exposing the electrical contact means for mating engagement with the prongs of said plug.

Still another object of this invention resides in the fact that the shutter is formed with a horizontal cam projecting from its body into one of the entrance passageways for cooperation with one of the prongs of the plug whereby the shutter may be cammed by said prong to a position exposing the electrical contacts within the socket or receptacle.

Another object of this invention resides in the fact that the electrical socket or receptacle comprising the subject matter of this invention is simple in design, requires a minimum number of parts to fabricate, and is foolproof in its intended operation.

Other objects Will appear hereinafter.

For the purpose of illustrating the invention, there is shown in the drawings a form which is presently pre ferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.

FIGURE 1 is a longitudinal cross sectional view through the electrical socket comprising the subject matter of the instant invention.

FIGURE 2 is a cross sectional view taken substantially along the plane indicated by the line 2-2 in FIGURE 1.

FIGURE 3 is a cross sectional view taken substantially along the plane indicated by the line 33 in FIG- URE 1.

FIGURE 4 is a cross sectional view similar to FIG- URE 1 but illustrating a slightly modified form of the invention.

3,222,631- Patented Dec. 7, 1965 FIGURE 5 is an exploded perspective view of the form of the invention illustrated. in FIGURE 4.

Referring now to the drawing in detail, the electrical socket comprising the subject matter of the instant invention is generally designated by the numeral 10.

As disclosed, the electrical socket 10 includes a body portion 12 which may be encased within a rectangular attaching plate or frame 14. The body portion 12 of the socket It) may be disposed within a recess in a wall 16 and the attaching plate 14 may be used to secure the body portion to the wall. Alternatively, the electrical socket concept of this invention may be incorporated into a female-type plug connector Without departing from the scope of the inventior.

A pair of female contact elements 18 and 20 may be secured to opposite sides of the body 12 of the socket 10. A pair of fastening elements, such as 26 and 28, act as means for securing electrical conductors 22 and 24 to the contact elements.

A pair of entranceways 30 and 32 is formed in the front face 33 of the socket 10 for receiving the prongs 34 and 36 of an electrical plug 38. The entranceways 30 and 32 are aligned with the female contact elements 13 and 20 respectively whereby upon linear movement of the prongs 34 and 36 within the entranceways 3i) and 32, an electrical contact would be normally established between the prongs 34 and 36 and the contact elements 18 and 20.

However, means are positioned within the entranceways 30 and 32 for blocking access to the electrical con tacts 18 and 20. This means includes a shutter 40 slidable in a slot 41 oriented perpendicular to the entranceways 30 and 32. A coil spring 46 normally urges the shutter 46 to a position wherein access to the female contact elements 18 and 20 through the entrance passages 30 and 32 is blocked.

The shutter 40 is provided with a pair of elongated apertures 42 and 44 which, if aligned with the entrance ways 30 and 32, would expose the elect.1cal contact means to the prongs 34 and 36 inserted within the entrance passageways.

The shutter 40 is also provided with a plurality of notches 48, 50, 52 and 54 out along opposed edges thereof and normally aligned with the passageways 30 and 32 under the urging of the spring 46. Cooperating with these notches are a plurality of leafsprings 62, 64, 66 and 68 to lock the shutter in its normally urged position. The leafsprings are each housed within a spring housing 58 in the body portion 12. The housings are positioned over and under each of the passageways 30 and 32. Each of the springs includes a central V-shaped portion 70 extending from its respective housing 58 into one of the passageway 30, 32. A remote end 71 of each of the springs cooperates and is resiliently urged into one of the notches 4854 to securely hold the shutter in its blocking position.

Upon insertion of the prongs 34 and 36 into the entranceways 30 and 32, each of the prongs will strike the pair of opposing V-shaped portions of the opposed springs overlying and underlying each of the entrances. The prongs upon continued movement after striking the portion 79 of the springs will cam the remote end 71 thereof out of seated engagement with the notches in the shutter. This operatively conditions the shutter for sliding movement relative to the entrance passages 30 and 32. It should be appreciated that it is necessary for both prongs 34 and 36 to simultaneously enter the passages 30 and 32 to unlock the shutter 40. This is because of the arrangement of the leafsprings and notches adjacent each of the entranceways. Hence, the insertion of a metal wire or metallic object into one of the entranceways will not be enough to unlock the shutter and condition it for sliding movement. The prongs of the plug, in essence, act as a key.

Projecting from one surface of the shutter 40 into the entrance passage is a horizontal triangular plate 56. The plate 56 comprises a cam for moving the shutter laterally of the entrance passages to expose the electrical contacts to the prongs of the plug. This is accomplished upon continuous movement of the plug past the V-shaped portion 70 of the springs 6268 wherein the prong 34 will strike the cam 56 to impart lateral movement to the shutter against the bias of the coil spring 46. This movement of the shutter will cause the elongated apertures 42 and 44 to align with the entranceways 30 and 32. Continued movement of the prongs 34 and 36 of the plug 38 after the camming action has taken place will establish contact with the contact elements 18 and 26 since the prongs can pass through the shutter.

It should thus be apparent that an electrical socket has been disclosed wherein access to a source of electrical energy can only be gained by the insertion of the prongs of an electrical plug into the socket. Upon the continuous linear movement of the prongs into a pair of spaced entrance passages in the body portion of the socket, a shutter blocking access to the source of electrical energy is first unlocked by the prongs and conditioned for movement. Continued movement of the prongs causes the shutter to slide to a position presenting apertures to the prongs so that they may pass through the shutter. Further continuous movement of the prongs after they pass through the shutter establishes electrical contact with the source of electrical energy. In this manner, the dangerous situation which may be caused by the insertion of a wire or other metallic object into one of the passageways of the electrical socket is eliminated. The operation of the device does not require any other motion than the usual push to make an electrical connection and pull to disconnect.

The embodiment illustrated in FIGURES 4 and 5, incorporates the same operational features discussed above. Hence, the primed numerals indicate similar structure to the embodiment of the invention illustrated in FIGURES 1 to 3.

The embodiment of the invention illustrated in FIG- URES 4 and 5, illustrates that a standard electrical receptacle designated by the numeral 80 may be modified by an adapter receptacle 82 to provide the safety principles disclosed in conjunction with the present invention. The adapter 82 may be encased within a suitable attaching plate or frame 84. It is only necessary to connect the adapter 82 to the standard socket or receptacle 80 by means of one centrally located screw 86 threaded through the center of the adapter 82 into the standard socket or receptacle 80.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention.

I claim:

1. An electrical socket comprising a body portion, spaced entrance-ways in said body portion for receiving the prongs of an electrical plug, electrical contact means contiguous with said entrance-ways adapted to be connected to the prongs of an electrical plug received within said entrance-ways, a laterally slidable shutter disposed across said entrance-ways for blocking access to said electrical contact means in one position thereof and for exposing said electrical contact means in another position thereof, spring means for normally urging said shutter to a position across said entrance-ways blocking access to said electrical contact means, means for locking said shutter in said blocking position, said locking means including at least one notch cut in said shutter normally contiguous with each said entrance-way, and resilient springs housed within said body portion in seated engagement within each said notch for preventing the sliding of said shutter, each of said resilient springs including an integral portion protruding into said entrance-way and cammable by the prong of an electrical plug to unseat said resilient springs from their respective notches to thereby completely unlock said shutter means, and cam means responsive to the further insertion of the prongs for sliding said shutter to a position in said entrance-ways exposing said electrical contact means, said cam means for sliding said shutter in response to insertion of the prongs of an electrical plug into said entrance-ways to a position exposing said electrical contact means including a cam projecting from said shutter into said entranceways.

2. An electrical socket in accordance with claim 1 wherein said resilient springs include a first portion fixed to said body portion, a second portion seated within said notches, and said protruding portion, said protruding ortion being a V-shaped portion intermediate said first and second portions.

3. An electrical socket comprising a body portion, spaced entrance-ways in said body portion for receiving the prongs of an electrical plug, electrical contact means contiguous with the entrance-ways adapted to be connected to the prongs of an electrical plug received within said entrance-ways, a laterally slidable shutter disposed across said entrance-ways for blocking access to said electrical contact means, spring means for normally urging said shutter to a position across said entrance-ways blocking access to said electrical contact means in one position thereof and exposing said electrical contact means in another position thereof, means for locking said shutter in said blocking position, said locking means including a pair of notches cut in said shutter normally contiguous with each said entrance-Way, and resilient springs housed within said body portion in seated engagement within each of said notches for preventing the sliding of said shutter, each of said resilient springs including an integral portion protruding into said entrance-way and cammable by the prong of an electrical plug to unseat said resilient springs from said notches to thereby unlock said shutter, and cam means responsive to the further insertion of the prongs for sliding said shutter to a position across said entrance-ways exposing said electrical contact means, said cam means for sliding said shutter in response to insertion of the prongs of an electrical plug into said entrance-ways to a position exposing said contact means including a cam projecting from said shutter into said entrance-ways.

4. An electrical socket in accordance with claim 3 wherein said resilient springs include a first portion fixed to said body portion, a second portion seated within said notches, and said protruding portion, said protruding portion being a V-shaped portion intermediate said first and second portion.

References Cited by the Examiner UNITED STATES PATENTS 4/1939 Blinn 33940 X 12/1943 Blinn 339--40 

1. AN ELECTRICAL SOCKET COMPRISING A BODY PORTION, SPACED ENTRANCE-WAYS IN SAID BODY PORTION FOR RECEIVING THE PRONGS OF AN ELECTRICAL PLUG, ELECTRICAL CONTACT MEANS CONTIGUOUS WITH SAID ENTRANCE-WAYS ADAPTED TO BE CONNECTED TO THE PRONGS OF AN ELECTRICAL PLUG RECEIVED WITHIN SAID ENTRANCE-WAYS, A LATERALLY SLIDABLE SHUTTER DISPOSED ACROSS SAID ENTRANCE-WAYS FOR BLOCKING ACCESS TO SAID ELECTRICAL CONTACT MEANS IN ONE POSITION THEREOF AND FOR EXPOSING SAID ELECTRICAL CONTACT MEANS IN ANOTHER POSITION THEREOF, SPRING MEANS FOR NORMALLY URGING SAID TUBULAR TO A POSITION ACROSS SAID ENTRANCE-WAYS BLOCKING ACCESS TO SAID ELECTRICAL CONTACT MEANS, MEANS FOR LOCKING SAID SHUTTER IN SAID BLOCKING POSITION, SAID LOCKING MEANS INCLUDING AT LEAST ONE NOTCH CUT IN SAID SHUTTER NORMALLY CONTIGUOUS WITH EACH SAID ENTRANCE-WAY, AND RESILIENT SPRINGS HOUSED WITHIN SAID BODY PORTION IN SEATED ENGAGEMENT WITHIN EACH SAID NOTCH FOR PREVENTING THE SLIDING OF SAID SHUTTER, EACH OF SAID RESILIENT SPRINGS INCLUDING AN INTEGRAL PORTION PROTRUDING INTO SAID ENTRANCE-WAY AND CAMMABLE BY THE PRONG OF AN ELECTRICAL PLUG TO UNSEAT SAID RESILIENT SPRINGS FROM THEIR RESPECTIVE NOTCHES TO THEREBY COMPLETELY UNLOCK SAID SHUTTER MEANS, AND CAM MEANS RESPONSIVE TO THE FURTHER INSERTION OF THE PRONGS FOR SLIDING SAID SHUTTER TO A POSITION IN SAID ENTRANCE-WAYS EXPOSING SAID ELECTRICAL CONTACT MEANS, SAID CAM MEANS FOR SLIDING SAID SHUTTER IN RESPONSE TO INSERTION OF THE PRONGS OF AN ELECTRICAL PLUG INTO SAID ENTRANCE-WAYS TO A POSITION EXPOSING SAID ELECTRICAL CONTACT MEANS INCLUDING A CAM PROJECTING FROM SAID SHUTTER INTO SAID ENTRANCEWAYS. 